The drug maker’s shares fell nearly 30% to a market value of about $438 million in midday trading.

Avanir said in a release that its AVP-923 drug candidate for multiple sclerosis did not fare better than a placebo in clinical trials.

Mizuho Securities analyst Mario Corso downgraded Avanir from “buy” to “neutral” after the company released financial results for the three months ended Sept. 30. Avanir released its results after the market closed on Tuesday.

Avanir posted a net loss of $35.4 million in the period, compared to a net loss of $11.7 million in the year-ago quarter. The former number includes a $20 million one-time payment Avanir made for a migraine drug candidate called AVP-825 that it acquired from Pennsylvania-based OptiNose U.S. Inc.

Revenue grew 61% to $21.7 million, including $20.2 million in sales of Avanir’s core Nuedexta drug for treating pseudobulbar affect, a neurological disorder.